Lifting jack



June 19, 1928.

A. C. HOPKINS LIFTING JACK Filed March 26, 1927 A TTORNEYS 7 INVENTOR By firffior C //0 /r/'/1a iPatented June 19, 1928.

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ARTHUR C. HOPKINS, OF NILI E IS, MICHIGAN, ASSIGNOR TO NATIGNAL-STANDARD COM- PANY, OF NILES, MICHIGAN. i

LIFTING JACK.

Application filed March 2 8, 1927. Serial No. 178,589. 7

Them-ain object of this invention is to provide an improved liifting jack of the toggle type which is very powerful, has a'considerable throw, and may be compactly collapsed. i

A :lurther object is to provide a lifting jack of the class described which is economical in structure and at the same time strong and durable.

Objects pertaining to details and ec0n0- mies otmy'invention will appear from the description to follow. The invention is defined and pointed out in the claims.

A structure embodying the features of my invention is clearly illustrated inthe accompanying drawing, in which:

Fig. 1 is a side view of my improved lifting jack collapsed. V

Fig. 2 is a plan view thereof.

Fig. 3 is a vertical section on line 33 of Figs. 1 and 2. T V

Fig. 4 is a side elevation of the jack eX- tended. p I

Referring to th drawing, I provide a T- sliapedstandard 1 having a suitablebase 2. The standard is vertically slotted at 3 and the arms 4 are each madeup of two members 5 connected by cross pieces 6 and at their outer ends. ltwill be noted that the cross piece? is considerably longer than the cross. piece 6. The cross pieces have pivots 8 at their ends.

The actuating screw 9 is provided with right and left hand threads at its ends and is arranged in the slot 3 and provided with thrust collars 10 supporting the screw against longitudinal movement while permitting it to move vertically in the slot3.

Bell crank actuating levers 11 are mounted on the pivots 8, the short arms of these levers being connected by pivots 12 to the actuating members or nuts 13 having threaded engagement with the reversely threaded portions of the actuating screw.

Owing to the greater length of the cross piece 7 one pair of lifting levers is spaced farther than the other so that their ends are arranged in overlapping relation, the'levers swinging in parallel planes.

Mounted on the inner ends of the levers by means of pivots 14 are pairs of lifting links 15 pivotally connected at their upper ends by means of the pivot rod 16, these links having outwardly projecting shoulders 17 adjacent their upper ends which form supports or the head member 18. This head member has projecting lugs 19 and 20 resting on the shoulders 17 and the lugs 20 are longer than the lugs 19 so as to engage the shoulders of the outer links.

The head member has downwardly projecting ears disposed on the inside of the inner links and vertically slotted at 22 to engage the pivot pin 16. This allows for a relative vertical movement of the head member onthe links, see Figs. 1 ands, accommodating the swinging ot the lifting links and: consequent relative movement of their head supporting shoulders. 1

To permit complete collapsing the standard is provided with a recess 23 in its upper end adapted to receive the'pivot 16. V I

With. the parts thus arranged I provide apowerl'ul jack which may be very compactly collapsed and at the same 'time one which simple and economical in structure. Having thus described my invention what I clain'i as new and desire to secure by Letters Patentis: H r V 1. In a liftingjacks, a T-shaped standard providedwith a base and having a vertical slot in the upright thereof, the arms of said standard term nating 1n transverse cross pieces provided with pivots attheir ends, a

one pair of levers swings within. the planes of the other, pairs of links pivotally mounted on said lifting levers and pivotally connected to each other at their upper ends, said links being provided with outwardly projecting head supporting shoulders, and a head mounted on said shoulders and provided with depending ears disposed between said links and vertically slotted to receive their connecting pivot, said standard having a recess in its upper end adapted to receive said pin when the jack is fully collapsed.

2. In a lifting jack, a T-shaped standard I provided with a base and having a vertical slot in the upright thereof, the arms of said standard terminating in transverse cross pieces provided with. pivots at their ends, a right and left hand actuating screw disposed in said slot in said standard for vertical movement th-ereinandprovided withthrust collars coacting with the sides of the standard to support the screw longitudinally, actuating members on said screw, pairs of bell crank lifting levers mounted on said pivots on said standard arms and pivotally connected to said actuating members, said cross plecesbeing of different lengths so that one pair of levers swings within the planes of 7 a reversely threaded actuating screw dis posed in saidslot in said standard for verti cal movement therein and provided with thrust collars supporting the screw against longitudinal movement, actuating members on said screw, bell crank lifting levers mounted onsaid standard arms in opposed relation toswing indifferent planes with their inner ends in overlapping relation, links pivotally mounted on the inner end of said lifting levers and pivotally connected at their upper ends, said links being provided with outwardly projecting head supporting shoulders, anda head mounted on said shoulders on said links and vertically slotted to receive their connecting pivot;

4. In a lifting ack, a standard, a reversely threaded actuating screw vmounted on said standard, actuating members on said screw, bell crank lifting levers mounted on said standard in opposed relation to swing in different planes with their inner ends in overlapping relation, links pivotally mou-nt disposed 'actuating screw mounted on said standard for vertical reciprocating movement and supported against longitudinal 'movei'nent, actuating members on said screw,

oppositely disposed lifting levers pivotally mounted on said standard pivotally connected to said actuating members, said levers being disposed with their inner ends in overlapping relation and to swing in parallel planes, pairs of links pivotally mounted on the inner endsof said lifting levers and pivotally connected to each other at their upper ends, and a head mounted on the upper ends of said links. r

' 6. In a lifting jack, the combination of'a standard, a ri -ht and left hand horizontally disposed actuating screw mounted on said standard for vertical reciprocating movement and supported against longitudinal movement, actuating members on said screw,

oppositely disposed'l-ifting levers pivotally mounted on said standard and pivotally con nected to said actuating members, pairs of links pivotally mounted on the inner ends 'of said lifting levers and pivotally connected to eachother at their upper ends, and ahead mounted on the upper ends of-said links.

, In witness "Whereof'I have hereunto set my hand. l

ARTHUR o; HOPKINS) 

